Determination of polycyclic aromatic hydrocarbons (PAHs) in shrimp.

A simple and rapid method for determining polycyclic aromatic hydrocarbons (PAHs) in shrimp is described. For sample preparation, the quick and simple QuEChERS procedure was used. Reverse-phase chromatography using an octadecyl silica (C18) column and water/acetonitrile gradient elution was used to separate analyte mixtures. After separation, PAHs were detected using liquid chromatography-tandem mass spectrometry (LC-MS/MS) equipped with the atmospheric pressure photoionization (PhotoSpray APPI) source operating in the positive-ion mode. In this methodology, all 16 common PAHs were used and toluene served as a charged dopant to efficiently ionize analyte molecules through secondary reactions. Spikes were performed at 0.2 and 1 μg/g with and without primary and secondary amine (PSA) sorbent cleanup. Recoveries of PAHs were good, with ion ratios that agreed well between the spikes and standards. Without cleanup at 0.2 μg/mL, seven compounds had relatively low recovery (49-69%) and one compound, naphthalene, had a somewhat high recovery of 129%. At 1 μg/mL without cleanup, only three compounds had slightly lower recovery (66-67%). When PSA cleanup was performed, all PAH recoveries were within 75-125% at both spike levels.